Normal operation is one thing, how about performance under fault conditions?
Opera is general-purpose finite element simulation software that is available for 2d and 3d analyses. Opera solves the fundamental equations that describe the intrinsic multi-physics behaviour of any power systems device. This formulation means that the software applies equally well to fault conditions and normal operation, and predicts accurately the real-life performance in either state.
Can Opera analyse a transformer under open-circuit, short-circuit and inrush conditions?
Yes, these are standard pre-configured analyses in the Transformers Environment. If you are not using the Environment then they can still be defined using the Modeller with its Circuit Editor.
Can Opera use my full hysteresis curve for my soft magnetic material?
In the Opera suite a semi-empirical method for modelling hysteresis has been developed alongside industrial partners. The magnetic behaviour is considered as a trajectory B(H). The trajectory is based on a measured major symmetric loop that is supplied by the user. This data may be easily obtained from measurements or published data-sheets, and imported into Opera as a magnetic characteristic table. The Opera hysteresis model includes the issues of nested minor loops and ‘wiping out’ of minor loops, which occurs when the trajectory goes through an earlier turning point. Moreover, the model recognises oscillating fields and minimises the storage of turning points. Assuming you have a licence for the applicable module, you need to supply data for only the major hysteresis loop. The algorithm uses a reconstruction technique to determine minor loops and turning points of the trajectory and to erase turning points when the magnetization of a material exceeds the previous excursion. The algorithm also correctly transfers to the saturated material curve beyond the end of the user data, in the same way as for anhysteretic materials in Opera.
Which variables can I use in an Opera Optimization process?
The optimization variables can be chosen from any of the user defined variables in Opera, in effect allowing geometry data, drives and even material data to be varied in order to obtain the desired objectives. Inequality and equality constraints can be defined in order to restrict the range of the design space. Different levels of constraints can be defined, depending on whether they can be evaluated as a feasible design during the model creation phase or they are obtained as an output of the finite element analysis. The Optimizer is capable of solving both single objective and multi-objective problems. The optimization objectives are defined as the output of the simulation and are evaluated and stored by the Optimizer. The output is an informative set of results which can be interrogated to choose the optimal design